Optical disc, optical disc reproducing method and apparatus, and recording method

ABSTRACT

An optical disc playback method is provided which includes steps of reading identification data recorded in an optical disc loaded in an optical disc player and starting reading data from a second recording area of the optical disc loaded in the optical disc player when it is determined that the loaded optical disc is a one having at least a first recording area and second recording area, a first lead-in area provided along the inner circumference of the first recording area, a second lead-out area provided along the outer circumference of the first recording area, a second lead-in area provided between the outer circumference of the first lead-out area and second recording area, and a second lead-out area provided along the outer circumference of the second recording area.

TECHNICAL FIELD

[0001] The present invention generally relates to an optical disc,optical disc playback method and apparatus, and an optical discrecording method, and more particularly to an optical disc such as amulti-session type one having a first session in which data is recordedin a first format and a second session in which data is recorded in asecond format, an optical disc playback method and apparatus for readingsuch data recorded in the optical disc, and an optical disc recordingmethod of recording such data in such a manner to an optical disc.

BACKGROUND ART

[0002] The conventional compact discs each being an optical disc includea CD-DA disc (Compact Disc-Digital Audio) having music data pre-recordedtherein, CD-ROM disc (Compact Disc-Read-Only Memory) having pre-recordedtherein text data, program data concerning computer software or thelike, CD-R disc (Compact Disc-Recordable) to which data can additionallybe recorded, CD-RW disc (Compact Disc-Rewritable) in which data can berewritten, and a CD-Extra disc (Compact Disc-Extra) having at least twotypes of data recorded in different recording areas thereof,respectively.

[0003] The disc drives for these types of compact discs include a firsttype being an audio device and dedicated for playback of the CD-DA disc,a second type installed in a personal computer (will be referred tosimply as “PC” hereunder) and compatible with all the compact discs ofthe above-mentioned types, and a third type installed in a PC andcapable of playing back all the compact discs of the above types andalso of recording data to the CD-R or CD-RW disc. The disc drive of thethird type can digitally copy data recorded in the CD-DA, CD-ROM orCD-Extra disc to the CD-R or CD-RW disc, that is, it can record dataread from any of the CD-DA, CD-ROM or CD-Extra discs as it is in thedigital form to the CD-R or CD-RW disc.

[0004] Note here that for digital copying of audio data recorded in theCD-DA disc to a magneto-optical disc, for example, the copyright for thedata recorded in the CD-DA disc is managed by the illegal copypreventive system such as SCMS (Serial Copy Management System) or thelike which allows only one copy of the data read from the CD-DA disc tothe magneto-optical disc.

[0005] However, the disc drive of the above third type normallyinstalled in a PC does not adopt the aforementioned illegal copypreventing system such as SCMS or the like. Namely, the disc drive ofthis type can make digital copy of data with no restrictions being puton the number of times such digital copy can be done. Therefore, thethird-type disc drive can make further digital copy of audio data,having been read from the CD-DA disc and digitally copied to a CD-R orCD-RW disc, to another CD-R or CD-RW disc. The user can use the first-,second- or third-type disc drive to play back the CD-R or CD-RW dischaving the audio data digitally copied thereto. Thus, the copyrightersuch as a recording company, artist or the like will have theircopyright breached by such illegal digital copying.

DISCLOSURE OF THE INVENTION

[0006] Accordingly, the present invention has an object to overcome theabove-mentioned drawbacks of the prior art by providing an optical discwhich cannot be played back by existing disc drives such as the first-,second-, third-type disc drive and the like, a method of recordinginformation signals to the optical disc, and an optical disc playbackapparatus and method for use with the optical disc.

[0007] The above object can be attained by providing an optical dischaving, according to the present invention, at least a first recordingarea and second recording area and in which a first lead-in area isprovided along the inner circumference of the first recording area, afirst lead-out area is provided along the outer circumference of thefirst recording area, a second lead-in area is provided between theouter circumference of the first lead-out area and the second recordingarea, and a second lead-out area is provided along the outercircumference of the second recording area. In the above optical disc,the second lead-in area, second recording area and second lead-out areaare formed at a smaller track pitch than in the first lead-in area,first recording area and first lead-out area, and the first lead-in areahas recorded therein identification data for the existence of at leastthe second recording area.

[0008] Also the above object can be attained by providing an opticaldisc playback method including, according to the present invention,steps of reading identification data recorded in an optical disc loadedin an optical disc player, and starting reading data from a secondrecording area of the optical disc loaded in the optical disc playerwhen it is determined based on the read identification data that theloaded optical disc is a one having at least first and second recordingareas, a first lead-in area provided along the inner circumference ofthe first recording area, a first lead-out area provided along the outercircumference of the first recording area, a second lead-in areaprovided between the outer circumference of the first lead-out area andthe second recording area, and a second lead-out area provided along theouter circumference of the second recording area.

[0009] Also the above object can be attained by providing an opticaldisc playback method including, according to the present invention,steps of reading medium identification data for an optical disc typefrom a lead-in area of an optical disc loaded in an optical disc player,and reading data from a second recording area when it is determinedbased on the read medium identification data that the optical discloaded in the optical disc player is a one in which a second lead-inarea, second recording area provided along the outer circumference ofthe second lead-in area and a second lead-out area provided along theouter circumference of the second recording area are formed at a smallertrack pitch than in a first lead-out area provided along the innercircumference of the second lead-in area, first recording area providedalong the inner circumference of the first lead-out area and a firstlead-in area provided along the outer circumference of the firstrecording area.

[0010] Also the above object can be attained by providing an opticaldisc playback method including, according to the present invention,steps of reading medium identification data for an optical disc typefrom a lead-in area of an optical disc loaded in an optical disc player,and reading data from a first recording area when it is determined basedon the read medium identification data that the optical disc loaded inthe optical disc player is a one in which a second lead-in area, secondrecording area provided along the outer circumference of the secondlead-in area and a second lead-out area provided along the outercircumference of the second recording area are formed at a smaller trackpitch than in a first lead-out area provided along the innercircumference of the second lead-in area, first recording area providedalong the inner circumference of the first lead-out area and a firstlead-in area provided along the outer circumference of the firstrecording area.

[0011] Also the above object can be attained by providing an opticaldisc player including, according to the present invention, a drive unitto rotate an optical disc loaded in the optical disc player, an opticalpickup to read data from the loaded optical disc, an actuator to movethe optical pickup radially of the loaded optical disc, and a controllerto control the operation of at least the actuator while identifying thetype of the loaded optical disc based on identification data read by theoptical pickup from the loaded optical disc. The controller controls theactuator to move the optical pickup and cause the optical to startreading data from a second recording area of the loaded optical discwhen it is determined that the loaded optical disc is a one having atleast first and second recording areas, a first lead-in area providedalong the inner circumference of the first recording area, a firstlead-out area provided along the outer circumference of the firstrecording area, a second lead-in area provided between the outercircumference of the first lead-out area and second recording area, anda second lead-out area provided along the outer circumference of thesecond recording area.

[0012] Also the above object can be attained by providing an opticaldisc player including, according to the present invention, a drive unitto rotate an optical disc loaded in the optical disc player, an opticalpickup to read data from the loaded optical disc, an actuator to movethe optical pickup radially of the loaded optical disc, and a controllerto control the operation of at least the actuator while identifying thetype of the loaded optical disc based on identification data read by theoptical pickup from the loaded optical disc. The controller controls theactuator to move the optical pickup and causes the optical pickup tostart reading data from the second recording area of the loaded opticaldisc when it is determined based on the medium identification data thatthe loaded optical disc is a one in which a second lead-in area, secondrecording area provided along the outer circumference of the secondlead-in area and a second lead-out area provided along the outercircumference of the second recording area are formed at a smaller trackpitch than in a first lead-out area provided along the innercircumference of the second lead-out area, first recording area providedalong the inner circumference of the first lead-out area and a firstlead-in area provided along the inner circumference of the firstrecording area.

[0013] Also the above object can be attained by providing an opticaldisc recording method including, according to the present invention,steps of forming a first lead-in area and first lead-out area at a firsttrack pitch from the inner circumference of an optical disc toward theouter circumference, forming a second lead-in area, second recordingarea and a second lead-out area at a smaller second track pitch than inthe first track pitch toward the outer circumference of the firstlead-out area; and recording, to the first lead-in area, at leastidentification data for the existence of the second recording area.

[0014] In the above optical disc, the first lead-in area has recordedtherein medium identification data indicating that the track pitch ofthe second lead-in area, second recording area and second lead-out areais smaller than in the first lead-in area, first recording area andfirst lead-out area.

[0015] These objects and other objects, features and advantages of thepresent invention will become more apparent from the following detaileddescription of the best mode for carrying out the present invention whentaken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 explains the optical disc playback system according to thepresent invention.

[0017]FIG. 2 is a plan view of a third optical disc according to thepresent invention.

[0018]FIG. 3 explains the Q subcode in the third optical disc.

[0019]FIG. 4 shows a flow of operations made in production of the thirdoptical disc.

[0020]FIG. 5 is a block diagram of a cutting apparatus to produce theglass disc used in production of the third optical disc.

[0021]FIG. 6 is a block diagram of a first optical disc player capableof playing back a first optical disc such as a CD-DA disc.

[0022]FIG. 7 is a block diagram of a second optical disc player capableof playing back both a first optical disc and a second optical disc suchas a CD-ROM disc.

[0023]FIG. 8 is a block diagram of a third optical disc player capableof playing back the third optical disc in addition to the first andsecond optical discs.

[0024]FIG. 9 explains how to control optical disc playback in theoptical disc player according to the present invention, in which FIG. 9Aexplains how to control the optical disc playback in the first opticaldisc player, FIG. 9B explains how to control the optical disc playbackin the second optical disc player and FIG. 9C explains how to controlthe optical disc playback in the third optical disc player.

[0025]FIG. 10 shows a flow of operations made in a variant of the secondoptical disc player.

[0026]FIG. 11 shows a flow of operations made in a variant of the secondoptical disc player.

BEST MODE FOR CARRYING OUT THE INVENTION

[0027] Referring now to FIG. 1, there is schematically illustrated theoptical disc playback system according to the present invention. Theoptical disc playback system is generally indicated with a reference 1.The optical disc playback system 1 includes a first optical disc player40 capable of playing back a first optical disc, a second optical discplayer 60 capable of playing back the first optical disc and a secondoptical disc having data recorded therein in a format different from aone in which data is recorded in the first optical disc, and a thirdoptical disc player 80 capable of playing back, in addition to the firstand second optical discs, a third optical disc having data recordedtherein in formats different from ones in which data are recorded in thefirst and second optical discs.

[0028] In the present invention, the first optical disc is a CD-DA(Compact Disc-Digital Audio) disc having a first data such as audiodata, and the first optical disc player 40 is dedicated to playback ofthe first optical disc.

[0029] Also in the present invention, the second optical disc includes aCD-ROM (Compact Disc-Read-Only Memory) disc having data recorded in anarray different from a one in the first data, such as computer program,computer-processed data, etc., CD-R (Compact Disc-Recordable) disc,CD-RW (Compact Disc-Rewritable) disc, etc. Each of the optical discs ofthe second type has data recorded therein at the same track pitch as aone in which data is recorded in the first optical disc. The secondoptical disc may be either a single-session type optical disc having asession consisting of a lead-in area, a data area following the lead-inarea, and a lead-out area following the data area or a multi-sessiontype optical disc having multiple sessions. For example, the compactdisc of the multi-session type is a CD-Extra disc or the like havingaudio data or the like recorded in a first session defined along theinner circumference and computer program or the like recorded in asecond session defined along the outer circumference. It should be notedthat the number of sessions in the multi-session type optical discincluded in the second optical discs is not limited to two as above butit may be more than two. The second optical disc player 60 is installedin a PC or the like for example and can play back the second opticaldisc as well as the first optical disc. It should be noted that thesecond optical disc player 60 may be an optical disc recorder/playerhaving also a function to record data to a CD-R or CD-RW disc inaddition to the function of playing back such an optical disc.

[0030] Further, in the present invention, the third optical disc is amulti-session type optical disc having a first session defined along theinner circumference thereof and a second session defined along the outercircumference. The first session has a first data recorded therein atthe same track pitch as in the first and second optical discs, and thesecond session defined along the outer circumference has a third datarecorded therein at a smaller track pitch and with a higher density thanin the first and second optical discs. For example, the track pitch inthe first session is the same as in the first and second optical discs,that is, 1.5 to 1.6 μm. Audio data, video data or the like is recordedin the first session while audio data or the like higher in quality thanthe audio data recorded in the first data area 2 b. It should be notedthat the number of sessions in the third optical disc is not limited totwo but it may be more than two and that the third optical disc may be arecordable optical disc. The third optical disc player 80 can play backthe third optical disc as well as the first and second optical discs,that is, it can read data from an area in which data is recorded at asmaller track pitch, and with a higher density, than in the first andsecond optical discs, namely, from a second data area of the secondsession.

[0031] In the aforementioned optical disc playback system 1, thecopyrighter of a content recorded in the third optical disc loaded inthe second optical disc player 60 can be protected by inhibiting thesecond optical disc player 60 from reading the data from the thirdoptical disc. More particularly, since data is recorded in the firstsession of the third optical disc loaded in the second optical discplayer 60 at the same track pitch as in the first or second opticaldisc, data can be read from the first session but data cannot be readfrom the second session because the data is recorded in the secondsession of the third optical disc at a smaller track pitch than in thefirst session.

[0032] Next, the third optical disc, generally indicated with areference 2, according to the present invention will be described withreference to FIG. 2. The third optical disc 2 is a read-only opticaldisc composed of a disc substrate formed from a synthetic resin such aspolycarbonate and on which a train of pits corresponding to recordingdata is stamped by a stamper, a reflective layer formed on the side ofthe disc substrate on which the train of pits is formed, and aprotective layer formed on the reflective layer. As shown in FIG. 2, thethird optical disc 2 has provided thereon a first lead-in area 2 aformed around the center hole in the optical disc and which is to be afirst TOC (table of contents) area, a first data area 2 b provided alongthe outer circumference of the first lead-in area 2 a and to which afirst or second data is to be recorded, a first lead-out area 2 cprovided along the outer circumference of the first data area 2 b, asecond lead-in area 2 d provided along the outer circumference of thefirst lead-in area 2 c and which is to be a second TOC area, a seconddata area 2 e provided along the outer circumference of the secondlead-in area 2 d and to which a third data is to be recorded, and asecond lead-out area 2 f provided along the outer circumference of thesecond data area 2 e. That is, the third optical disc 2 is amulti-session type disc-shaped recording medium having a first session 3defined along the inner circumference thereof and consisting of thefirst lead-in area 2 a, first data area 2 b and first lead-out area 2 dand also a second session 4 defined along the outer circumference andconsisting of the second lead-in area 2 d, second data area 2 e andsecond lead-out area 2 f.

[0033] As shown in FIG. 3, in the above third optical disc 2, the trackpitch in the first session 3 is the same as in the first and secondoptical discs, while the track pitch in the second session 4 is smallerthan in the first session 3 and the recording density is lower than inthe first session 3. To the first data area 2 b, there are to berecorded audio data which is a first data, and computer program,computer-processed audio data, computer-processed video data or the likewhich is a second data, for example. To the second data area 2 e, thereis to be recorded high-quality audio data or the like which is morevaluable than audio data recorded in the first data area 2 b, forexample. It should be noted that the “quality audio data” referred toherein is data whose sampling rate is higher than that for the firstdata or whose quantizing step size is smaller than that of the firstdata.

[0034] Next, the Q subcode in the first lead-in area 2 a of the thirdoptical disc 2 will be described with reference to FIG. 3. The Q subcodeincludes a 2-bit sync block SYNC, 4-bit control block CNT, address blockADR, 4-bit track number block TNO, 8-bit point block POINT, 24-bitelapsed time block TIME, 8-bit zero block ZERO (in which “0” isrecorded), 24-bit primary time block PTIME, and a 16-bit error detectionblock CRC.

[0035] The elapsed time block TIME consists of an 8-bit minutes blockMIN indicating minutes of an elapsed time, 8-bit seconds block SECindicating seconds of the elapsed time, and an 8-bit frame block FRAMEindicating a frame number. The primary time block PTIME also consists ofan 8-bit minutes block PMIN indicating minutes of a primary time, 8-bitseconds block PSEC indicating seconds of the primary time, and an 8-bitframe block PFRAME indicating a frame number.

[0036] The control block CNT has recorded therein a number of channelsand pre-emphasis selection data. It has also recorded thereinidentification data for identifying which the third optical disc 2 is, aone for computer program, computer-processed data or the like or a onededicated for audio data. It should be noted that the second opticaldisc has recorded in the control block CNT thereof identification datafor identifying the optical disc 2 itself and the first optical disc foraudio data.

[0037] The address block ADR has recorded therein identification datafor a format including the track number block TNO, point block POINT,elapsed time block TIME, zero block ZERO and primary time block PTIME.It has also recorded therein identification data for identifying whichthe third optical disc 2 is, a multi-session type one or single-sessiontype one.

[0038] The track number block TNO is an area where a track number isrecorded, and the lead-in area has “00” recorded therein. It should benoted that the track number block TNO may have recorded thereinidentification data for discriminating the first and second opticaldiscs from the third optical disc 2.

[0039] The point block POINT has recorded therein data for definingcontents of record in the minutes block PMIN, seconds block PSEC andframe block PFRAME.

[0040] Each of the minutes block MIN, seconds block SEC and frame blockFRAME included in the elapsed time block TIME has an absolute time(absolute address) recorded therein.

[0041] The zero block ZERO in the third optical disc 2 has recordedtherein identification data for discriminating the first and secondoptical discs from the third optical disc 2. Of course, theidentification data may be recorded in the track number block TNO asmentioned above.

[0042] Each of the minutes block PMIN, seconds block PSEC and frameblock PFRAME included in the primary time block PTIME has content datarecorded therein based on the definitions in the point block POINT.

[0043] More particularly, the third optical disc 2 of the multi-sessiontype has recorded therein the first track number and last track numberin the first data area 2 b, leading address in the first lead-out area 2d, data on whether there is a next session, leading address and firsttrack number in the second lead-in area 2 d of the second session 4,etc. It should be noted that the second optical disc of themulti-session type has similar data recorded therein.

[0044] The error detection block CRC has recorded therein errordetection code such as CRC (Cyclic Redundancy Code) or the like. Theerror detection block CRC detected any error in the control block CNT,address block ADR, track number block TNO, point block POINT, elapsedtime block TIME, zero block ZERO and primary time block PTIME.

[0045] Note that the identification data indicating which the thirdoptical disc 2, a multi-session type one or a single-session type one,may be recorded in the address block ADR of the Q subcode in the firstlead-in area 2 a as well as that of the Q subcode in the first data area2 b and first lead-out data 2 c. Also, it should be noted that also theidentification data for discriminating the third optical disc 2 from thefirst and second optical discs may be recorded in the track number blockTNO and zero block ZERO in the Q subcode in the first data area 2 b andfirst lead-out area 2 c.

[0046] In the aforementioned third optical disc 2, the address block ADRof the Q subcode in the first lead-in area 2 a has recorded thereinidentification data indicating which the third optical disc 2 is, amulti-session type one or single-session type one. So, when the thirdoptical disc 2 is loaded in the second optical disc player 60 or thirdoptical disc player 80, data reading can preferentially be started atthe second session 4. Solely in the third optical disc player 80, datareading can be made from a recording area of the third optical disc 2,namely, from the second session 4, in which the track pitch is smallerthan in the first and second optical discs. In the second optical discplayer 60, however, since the track pitch in the second session 4 issmaller than in the first session 3, data reading cannot be made fromthe second session 4.

[0047] In the first lead-in area 2 a of the third optical disc 2, thetrack number block TNO and zero block ZERO of the Q subcode haverecorded therein identification data for discriminating the thirdoptical disc 2 from the first and second optical discs 5 and 6. Thus,the third optical disc player 80 can preferentially read from the secondsession 4 in the third optical disc 2, and the second optical discplayer 60 capable of reading the identification data can preferentiallyread data from the third optical disc 2. Since th track pitch in thefirst session 3 is the same as in the first and second optical discs,the second optical disc player 60 cannot read data from the firstsession 3.

[0048] Next, how to produce the third optical disc 2 according to thepresent invention will be described with reference to FIG. 4. As shown,a glass disc is coated with a photoresist in a photoresist coating step11, and a pattern of pits corresponding to data to be recorded is cut inthe resist coating by modulating laser light emitted from a laser sourcein a cutting step 12 to provide a master. Next, the master on which thepit pattern has been formed by the laser cutting is conveyed to adeveloping/fixing step 13 where the photoresist is developed and fixed.Thereafter, in a mother preparing step 14, the master is plated on thesurface to provide a mother. Next, in a stamper preparing step 15, themother is used to provide a stamper. In a replicating step 16, thestamper is placed in a mold and a transparent resin such aspolycarbonate or acryl is injected into the mold by an injection moldingmachine to produce a replica. The pit pattern formed on the master inthe cutting step 12 is stamped on one side of the replica thus prepared.Next in a reflective layer forming step 17, a reflective layer is formedby sputtering or the like on the side of the replica on which the pitpattern is formed.

[0049] Next, in a protective layer coating step 18, the reflective layerformed in the reflecting layer forming step 17 is coated with aUV-setting resin by spin coating and irradiated with UV (ultravioletrays) to form a protective layer. For data reading, the third opticaldisc 2 thus produced is irradiated with a light beam at a side thereofopposite to the side on which the protective layer is formed

[0050] Referring now to FIG. 5, there is schematically illustrated inthe form of a block diagram a cutting apparatus to produce a master bycutting a pit pattern corresponding to data to be recorded with a laserlight in the aforementioned cutting step 12 in production of the thirdoptical disc 2. The cutting apparatus is generally indicated with areference 20. As shown, the cutting apparatus 20 includes a first datagenerator 21 to generate a first data to be recorded to the firstsession 3 of the third optical disc 2, for example, data error-correctedby Cross Interleave Reed-Solomon Code (CIRC) or the like and modulatedby EFM (Eight to Fourteen Modulation) or the like, a first subcodegenerator 22 to generate a subcode to be recorded to the first session 3(as shown in FIG. 3), a second data generator 23 to generate a thirddata to be recorded to the second session 4 of the third optical disc 2,for example, error-corrected and modulated high quality audio data orthe like, a second subcode generator 24 to generate a subcode to berecorded to the second session 4, a first recording data generator 25 togenerate data to be recorded to the first session 3 by mixing togetherdata output from the first data generator 21 and data generated by thefirst subcode generator 22, and a second recording data generator 26 togenerate data to be recorded to the second session 4 by mixing togetherdata output from the second data generator 23 and data generated by thesecond subcode generator 24.

[0051] The cutting apparatus 20 further includes a laser emitter 27formed from a gas laser source such as argon laser, He-Cd laser or thelike, an optical modulator 28 such as EOM (Electro-Optical Modulator)using the Pockels effect or AOM (Acoustic-Optical Modulator) usingultrasound to modulate laser light emitted from the emitter 27 based onrecording data, a switch 29 to selectively output recording datagenerated by the first recording data generator 25 or recording datagenerated by the second recording data generator 26 to the opticalmodulator 28, a mirror 30 to deflect the optical path by reflecting thelaser light modulated by the optical modulator 28, a mechanism 31 tomove the mirror 30, an objective lens 33 to collect the laser lightreflected by the mirror 30 and irradiate it to a glass disc 32, a motor34 to rotate the glass disc 32, and a controller 35 to control thesystem operation.

[0052] The cutting apparatus 20 constructed as above functions as willbe described below. First, a pit pattern corresponding to a first datato be recorded to the first session 3 in the third optical disc 2 isprovided along the inner circumference of the glass disc 32, and then apit pattern corresponding to a second data to be recorded to the secondsession 4 in the third optical disc 2 is formed contiguous to the formerpit pattern and along the outer circumference of the glass disc 32. Morespecifically, the first data generator 21 makes error-correction coding,by CIRC or the like, and modulation, by EFM or the like, of data togenerate data to be recorded to the first session 3 in the third opticaldisc 2. At the same time, the first subcode generator 22 generates asubcode for the data which is to be recorded to the first session 3.Particularly, the first subcode generator 22 generates data about the Qsubcode shown in FIG. 3 and including identification data for indicatingwhich the third optical disc 2 is, a multi-session type optical disc ora single-session optical disc and identification data for discriminatingthe third optical disc 2 from the first and second optical discs 5 and6. The second data generator 23 makes error-correction coding, by CIRCor the like, and modulation, by EFM or the like, of data to generatedata to be recorded to the second session 4 in the third optical disc 2.At the same time, the second subcode generator 24 generates a subcodefor the data which is to be recorded to the second session 4.

[0053] First, for recording, to the glass disc 32, data to be recordedto the first session 3 in the third optical disc 2, the first recordingdata generator 25 is supplied with the data generated by the first datagenerator 21 and a subcode generated by the first subcode generator 22,and also with a part of the subcode generated by the second subcodegenerator 24 for recording to the second session 4 so that the addressesin the entire disc can be identified with data recorded in the TOC areain the first session 3. The first recording data generator 25 mixestogether the data from the first data generator 21, subcode from thefirst subcode generator 22 and subcode from the second subcode generator23 to generate data to be recorded to the first session 3 and providethe data to the optical modulator 28. At this time, the controller 35controls the switch 29 to connect the first recording data generator 25and optical modulator 28 to each other. On the other hand, the laseremitter 27 emits laser light which will be passed to the opticalmodulator 28. The optical modulator 28 modules the laser light based onthe recording data supplied from the first recording data generator 25in such a manner that a standard recording density can be attained. Thelaser light modulated by the optical modulator 28 is incident upon themirror 30. The mirror 30 is moved by the mirror moving mechanism 31 topermit to scan the laser light between the inner and outercircumferences of the glass disc 32. The laser light reflected by themirror 30 is condensed by the objective lens 33 and projected onto theglass disc 32 being rotated by the motor 34. Thus, the glass disc 32 iscut correspondingly to the recording data to form a latent image of thepit pattern.

[0054] For recording, to the glass disc 32, data to be recorded to thesecond session 4 in the third optical disc 2 contiguously to the abovedata to be recorded to the first session 3, the second recording datagenerator 26 is supplied with the data generated by the second datagenerator 23 and subcode generated by the second subcode generator 24.The second recording data generator 26 mixes together the data from thesecond data generator 23 and subcode from the second subcode generator24 to generate data to be recorded to the second session 4 and providethe data to the optical modulator 28. At this time, the controller 35controls the switch 29 to connect the second recording data generator 26and optical modulator 28 to each other. Thus, the optical modulator 28modulates the laser light emitted from the laser emitter 27 based on therecording data supplied from the second recording data generator 26 insuch a manner that the track pitch in the second session 4 will besmaller than in the first session 3. The laser light modulated by theoptical modulator 28 is incident upon the mirror 30. The laser light hasthe optical path thereof bent by the mirror 30, while the mirror 30 ismoved by the mirror moving mechanism 31 so that the track pitch in thesecond session 4 will be smaller than in the first session 3, therebypermitting to scan the laser beam between the inner and outercircumferences of the glass disc 32. The laser light is condensed by theobjective lens 33 and projected onto the glass disc 32 being rotated bythe motor 34. Thus, the glass disc 32 is cut correspondingly to therecording data to form the pit pattern.

[0055] The stamper prepared in the stamper preparing step 15 in FIG. 4is formed from the glass disc 32 formed by the aforementioned cuttingapparatus 20 following the steps in FIG. 4.

[0056] Next, there will be described the first optical disc player 40capable of playing back the first optical disc, the second optical discplayer 60 capable of playing back the first and second optical discs,and the third optical disc player 80 capable of playing back the thirdoptical disc 2 as well as the first and second optical discs, allincluded in the optical disc playback system 1.

[0057] As shown in FIG. 6, the first optical disc player 40 for playbackof a first optical disc 5 includes an optical pickup 41 to read datarecorded in the first optical disc 5, an RF circuit 42 which is suppliedwith an output from the optical pickup 41, a servo circuit 43 to producefocusing servo signal and tracking servo signal for the objective lensbased on the output from the RF circuit 42, a drive motor 44 to rotate afirst optical disc 5 at a constant linear velocity, and a feed motor 45to move optical pickup 41 radially of the first optical disc 5.

[0058] The first optical disc player 40 further includes a first decoder46 to subject the output from the RF circuit 42 to decoding processessuch as demodulation, error correction, de-interleaving, etc., a subcodeextraction circuit 48 to extract subcodes from the output from the RFcircuit 42, a D/A converter 49 to convert the digital data decoded inthe first decoder 46 to analog data, a speaker 50 to output audio dataetc. converted to the analog data, a display unit 51 to display addressinformation etc., an operation unit 52 provided with a play button,forward track jump button, backward track jump button, play stop button,etc. which are to be operated by the user, and a controller 53 tocontrol the operation of the entire first optical disc player 40. Thecontroller 53 includes a microcomputer.

[0059] The RF circuit 42 produces RF signal, focusing error signal andtracking error signal based on the output signal from a photodetector(not shown) included in the optical pickup 41. For example, the focusingerror signal is produced by the so-called astigmatism method, and thetracking error signal is produced by the so-called 3-beam method orpush-pull method. The RF circuit 42 provides the RF signal to the firstdecoder 46 while providing the focusing error signal and tracking errorsignal to the servo circuit 43.

[0060] The servo circuit 43 produces servo signal for use to play backthe first optical disc 5. More specifically, the servo circuit 43produces focusing servo signal based on the supplied focusing errorsignal so that the focusing error signal will be “0”, and it alsoproduces tracking servo signal based on the supplied tracking errorsignal so that the tracking error signal will be “0”. The servo circuit43 supplies the thus produced focusing and tracking servo signals to adrive circuit for an objective lens drive mechanism (not shown) of theoptical pickup 41. The drive circuit drives the objective lens drivemechanism (not shown) of the optical pickup 41 based on the suppliedfocusing and tracking servo signals. The objective lens drive mechanismdrives the objective lens. More specifically, the drive circuit drivesthe objective lens drive mechanism based on the supplied focusing servosignal to move the objective lens in a focusing direction parallel tothe optical axis of the objective lens, and based on the suppliedtracking servo signal to the objective lens in a tracking directionorthogonal to the optical axis of the objective lens. The servo circuit43 provides the drive motor 44 with servo signal for servo control ofthe drive motor 44 to drive the drive motor 44 to rotate the firstoptical disc 5 at a constant linear velocity, for example. A disc tableto rotate the optical disc is fixed to the rotation shaft of the drivemotor 44. The first optical disc 5 is set on the disc table, and rotatedalong with the disc table.

[0061] The first decoder 46 is dedicated to decoding of the first dataread from the first optical disc 5. More particularly, the first decoder46 demodulates EFM-modulated audio data from the RF circuit 42 andsubjects the data to decoding processes such as error correction by CIRCor the like and de-interleaving. The first decoder 46 provides thedecoded audio data etc. to the D/A converter 49.

[0062] The subcode extraction circuit 48 is provided to extract, fromthe RF signal produced by the RF circuit 42, P and Q subcodes recordedin the TOC area, data area and lead-out area. The subcode extractioncircuit 48 provides the subcodes extracted from the TOC data, namely,address information, track number, etc. to the controller 53.

[0063] The controller 53 controls the entire first optical disc player40. More particularly, the controller 53 provides the addressinformation, track number, etc. supplied from the subcode extractioncircuit 48 to the display unit 51 and causes the display unit 51 todisplay the address information, track number, etc. Supplied withcontrol signal from the operation unit 52 operated by the user, thecontroller 53 selects an operation of the first optical disc player 40according to the input control signal and controls the first opticaldisc player 40.

[0064] For example, when supplied with play start signal from theoperation unit 52, the controller 53 controls the feed motor 45 to movethe optical pickup 41 to the lead-in area so that the optical pickup 41can read TOC data such as subcodes from the lead-in area provided alongthe innermost circumference of the first optical disc 5, in order tostart reading audio data etc. from the first track.

[0065] The first optical disc player 40 constructed as above functionsas will be described below. For example, when a play start button on theoperation unit 52 is pressed by the user, the controller 53 will drivethe drive motor 44 to rotate the first optical disc 5 at a constantlinear velocity of rotation, and put the feed motor 45 into operation tomove the optical pickup 41 to read TOC data such as subcodes from thelead-in area of the first optical disc 5. The optical pickup 41 havingbeen moved to a position where it is opposite to the lead-in area willirradiate light beam to the signal recording surface of the firstoptical disc 5. The return light from the signal recording surface ofthe first optical disc 5 is converted to electric signal by aphotodetector (not shown) of the optical pickup 41. The photodetectorprovides the electric signal to the RF circuit 42. The RF circuit 42produces RF signal and provides it to the first decoder 46 whileproducing focusing and tracking error signals and providing them to theservo circuit 43.

[0066] The servo circuit 43 produces focusing and tracking servo signalsbased on the input focusing and tracking error signals and provides theerror signals to the drive circuit of the objective lens drive mechanism(not shown) of the optical pickup 41. The optical pickup 41 drives theobjective lens drive mechanism (not shown) to move the objective lens inthe direction of the optical axis of the light beam for focusing controland in a direction orthogonal to the optical axis of the light beam fortracking control.

[0067] The subcode extraction circuit 48 is provided to extract subcodesfrom the RF signal, and provides it to the controller 53. The controller53 controls the system operation based on the input subcode. Forexample, the first decoder 46 makes demodulation, error correction andde-interleaving of the RF signal supplied from the RF circuit 42, andprovides the processed RF signal to the D/A converter 49. The D/Aconverter 49 converts the digital signal to analog signal, and providesthe analog signal to the speaker 50. The speaker 50 converts the analogsignal to a sound and outputs it as a audible sound. The controller 53controls the display unit 51 to display the address information, tracknumber, etc. extracted from the subcode.

[0068] Next, there will be described the second optical disc player 60adapted to play back the first optical disc 5 and second optical disc 6.According to the present invention, the second optical disc player 60 isnormally used in a PC or the like. As shown in FIG. 7, the secondoptical disc player 60 includes an optical pickup 61 to read datarecorded in the first optical disc 5 and second optical disc 6, an RFcircuit 62 which is supplied with an output from the optical pickup 61,a servo circuit 63 to produce focusing servo signal and tracking servosignal for a objective lens (not shown) provided in the optical pickup61 based on the output from the RF circuit 62, a drive motor 64 torotate a first optical disc 5 or second optical disc 6 at a constantlinear velocity, and a feed motor 65 to move the optical pickup 61radially of the first optical disc 5 and second optical disc 6.

[0069] The second optical disc player 60 further includes a firstdecoder 66 to subject the output from the RF circuit 62, correspondingto a signal read from the first optical disc 5, to decoding processessuch as demodulation, error correction, de-interleaving, etc., a seconddecoder 67 to subject the output from the RF circuit 62, correspondingto a signal read from the second optical disc 6, to decoding processessuch as demodulation, error correction, de-interleaving, etc., a switch68 to selectively connect the output from the RF circuit 62 to any ofthe first and second decoders 66 and 67, a subcode extraction circuit 69to extract subcodes from the TOC data read from the first and secondoptical discs 5 and 6 and supplied from the RF circuit 62, a D/Aconverter 70 to convert the digital data decoded in the first and seconddecoders 66 and 67 to analog data, a speaker 71 to output audio dataetc. converted to the analog data, a monitor 72 to display addressinformation, track number, etc. recorded in the first optical disc 5 andalso data based on a computer program, etc. recorded in the secondoptical disc 6, an interface (will be referred to simply as “I/F”hereunder) 73 providing a connection between the second decoder 67 andmonitor 72, an operation unit 74 including a mouse, keyboard, ten keys,etc. to be operated by the user, and a controller 75 to control thesystem operation. The controller 75 includes a microcomputer.

[0070] As above, the second optical disc player 60 is different from thefirst optical disc player 40 in that it additionally includes the seconddecoder 67 to play back the second optical disc 6 and switch 68 toselect either the first and second decoders 66 and 67. It should benoted that the same circuits in the second optical disc player 60 as inthe first optical disc player 40 will not be described any more.

[0071] The second decoder 67 is provided to demodulate second data suchas computer program etc. recorded in the second optical disc 6 andhaving been read from the second optical disc 6 and EFM-modulated andsupplied from the RF circuit 62, and subjects the demodulated seconddata to decoding processes such as error correction and de-interleaving.The second decoder 67 provides the decoded data to either the I/F 73 orD/A converter 70 depending upon the type of the data.

[0072] For playback of the first optical disc 5, the switch 68 connectsthe RF circuit 62 and first decoder 66 to each other for the RF signalto be supplied from the RF circuit 62 to the first decoder 66. Forplaying back the second optical disc 6, the switch 68 will make aconnection between the RF circuit 62 and second decoder 67 for the RFsignal to go from the RF circuit 62 to the second decoder 67.

[0073] The controller 75 provides a control as follows in addition tothe control by the controller 53 of the first optical disc player 40.That is, when supplied with the sib-code data read from the first andsecond optical discs 5 and 6, which is supplied from the subcodeextraction circuit 69, the controller 75 determines, based on thesubcode, the optical disc set on the disc table to be the first opticaldisc 5 or second optical disc 6. More specifically, when there isdetected the identification data for the second optical disc 6, recordedin the control block CNT of the Q subcode included in the TOC data asshown in FIG. 3, the controller 75 will control the switch 68 to connectthe RF circuit 62 and second decoder 67 to each other.

[0074] Also, when there is detected the identification data for themulti-session type optical disc, recorded in the address block ADR ofthe Q subcode included in the TOC data as shown in FIG. 3, thecontroller 75 will control the feed motor 65 to move the optical pickup61 to a position where it will be able to read data recorded in thelead-in area in the second session 4 defined along the outercircumference so that data can preferentially be read from the secondsession 4 defined along the outer circumference.

[0075] Further, when the optical disc to be played back is determined tobe of the multi-session type and reading of the second session 4 definedalong the outer circumference is started, the controller 75 willdetermine, based on the identification data indicating the type of datarecorded in the control block CNT in the subcode included in the TOCdata recorded in the lead-in area of the second session 4, which candecode the data read from the second session 4, the first decoder 66 orsecond decoder 67. It should be noted that the system may be adaptedsuch that for determination of the first decoder 66 or second decoder 67to be an appropriate one, the controller 75 causes both the firstdecoder 66 and second decoder 67 to decode the data on trial bycontrolling the switch 68 to select each of the decoders. When thecontroller 75 determines that neither the first decoder 66 nor thesecond decoder 67 can decode the data, it will stop the optical pickup61 from playback operation and the drive motor 64 from driving, andeject the loaded optical disc from the second optical disc player 60.

[0076] When the controller 75 determines that the optical disc loaded inthe apparatus 60 is of the multi-session type, the controller 75 maycontrol the second optical disc player 60 as follows. That is, thecontroller 75 controls the feed motor 65 to move the optical pickup 61to a position where it will be able to read the TOC data recorded in thelead-in area of the first session 3 defined along the innercircumference so that reading data from the first session 3 definedalong the inner circumference will be started when it is detected at thestart of reading the second session 4 defined along the outercircumference that the second decoder 67 cannot decode the data.

[0077] The controller 75 controls the feed motor 65 to move the opticalpickup 61 to a position where it will be able to read the TOC datarecorded in the lead-in area in the first session 3 defined along theinner circumference so that data will be read from the first session 3defined along the inner circumference without access to the secondsession 4 defined along the outer circumference when it is detectedbased on the data read from the address block ADR in the subcode thatthe optical disc to be played back is of the multi-session type and alsothere is detected from the zero block ZERO identification data for thethird optical disc 2.

[0078] The second optical disc player 60 constructed as above functionsas will be described below. For example, when a play start button on theoperation unit 74 is pressed by the user, the controller 75 will drivethe drive motor 64 to rotate the loaded optical disc at a constantlinear velocity of rotation, and put the feed motor 65 into operation tomove the optical pickup 61 to read TOC data such as subcodes from thelead-in area provided along the innermost circumference of the firstoptical disc 5. The optical pickup 61 detects return light from theoptical disc by a photodetector of the optical pickup 61, converts it toelectric signal and provides the signal to the RF circuit 62. Thesubcode extraction circuit 69 provides extracted subcode to thecontroller 75. The controller 75 determines, based on the identificationdata recorded in the control block CNT in the subcode, which the opticaldisc set on the disc table is, the first optical disc 5 or secondoptical disc 6, and also based on the identification data recorded inthe address block ADR in the subcode, which the optical disc is, themulti-session type or single-session type.

[0079] When the identification data for the second optical disc 6 hasnot been detected from the control block CNT in the subcode recorded inthe lead-in area, the controller 75 determines that the optical disc seton the disc table is the first optical disc 5 and controls the switch 68to make a connection between the RF circuit 62 and first decoder 66.Similarly to the first optical disc player 40, the second optical discplayer 60 decodes the read first data by the first decoder 66 andprovides the decoded data from the speaker 71 via the D/A converter 70.

[0080] When it is determined based on the data in the control block CNTin the subcode recorded in the lead-in area, the controller 75determines that the second optical disc 6 is set on the disc table andcontrols the switch 68 to make a connection between the RF circuit 62and second decoder 67. In the second optical disc player 60, the readsecond data is decoded by the second decoder 67, the decoded data ispassed to the monitor 72 via the I/F 73 or it is outputted by thespeaker Similarly to the first optical disc player 40, the secondoptical disc player 60 decodes the read first data by the first decoder66 and provides the decoded data from the speaker 71 via the D/Aconverter 70.

[0081] Further, when the identification data indicating that the loadedoptical disc is of the multi-session type is detected from the addressblock ADR in the subcode in the lead-in area, the controller 75 drivesthe feed motor 65 to move the optical pickup 61 to a position where itwill be able to read the TOC data such as subcodes from the lead-in areain the second session 4 defined along the outer circumference of thesecond optical disc 6. The controller 75 determines the type of thedecoder based on the identification data in the control block CNT in thesubcode recorded in the lead-in area in the second session 4 definedalong the outer circumference, and controls the switch 68 to make aconnection between the RF circuit 62 and first decoder 66 or seconddecoder 67. In the second optical disc player 60, the data read from thesecond session 4 is decoded by the first decoder 66 or second decoder67, and provided via the I/F 73 to the monitor 72 on which acorresponding display will be made, or via the D/A converter 70 to thespeaker 71.

[0082] When the operation unit 74 is operated by the user for readingthe first session 3 defined along the inner circumference aftercompletion of reading the second session 4 defined along the outercircumference, the controller 75 drives the feed motor 65 to move theoptical pickup 61 to a position it will be able to read the TOC datasuch as subcodes from the lead-in area in the first session 3 definedalong the inner circumference of the second optical disc 6. By readingthe identification data in the control block CNT in the subcode from thelead-in area in the first session 3 defined along the innercircumference, the controller determines the type of the decoder, andcontrols the switch 68 to make a connection between the RF circuit 62and first second 66 or second decoder 67. In the second optical discplayer 60, the first data or second data read from the first session 3is decoded by the first decoder 66, and provided via the I/F 73 to themonitor 72 on which a corresponding display will be made, or via the D/Aconverter 70 to the speaker 71.

[0083] Next, there will be described the third optical disc player 80adapted to read information signals recorded in the first optical disc5, second optical disc 6 and third optical disc 2. As shown in FIG. 8,the third optical disc player 80 includes an optical pickup 81 to readdata recorded in the first, second and third optical discs 5, 6 and 2,an RF circuit 82 which is supplied with an output from the opticalpickup 81, a servo circuit 83 to produce focusing and tracking servosignals for the objective lens (not shown) in the optical pickup 81based on the output from the RF circuit 82, a drive motor 84 to rotatethe first, second or third optical disc 5, 6 or 2 at a constant linearvelocity, and a feed motor 85 to move the optical pickup 81 radially ofthe first, second and third optical discs 5, 6 and 2.

[0084] The third optical disc player 80 further includes a first decoder86 to subject the output from the RF circuit 82, which is based on asignal read from the first optical disc 5, to decoding processesincluding demodulation, error correction, de-interleaving, etc., asecond decoder 87 to subject the output from the RF circuit 82, which isbased on a signal read from the second optical disc 6, to decodingprocesses include demodulation, error correction, de-interleaving, etc.,a third decoder 88 to subject the output from the RF circuit 82, whichis based on a signal read from the third optical disc 2, to decodingprocesses include demodulation, error correction, de-interleaving, etc.,a switch 89 to selectively provide the output from the RF circuit 82 tothe first, second or third decoder 86, 87 or 88, a subcode extractioncircuit 90 to extract subcodes from the TOC data read from the first,second and third optical discs 5, 6 and 2 and supplied from the RFcircuit 82, a D/A converter 91 to convert digital data decoded by thefirst, second and third decoders 86, 87 and 88 to analog data, a speaker92 to output audio data etc. converted to the analog signal, a monitor93 to display address information, track number, etc. recorded in thefirst optical disc 5 and third optical disc 2 and also display databased on computer program etc. recorded in the second optical disc 6, aninterface (will be referred to simply as “I/F” hereunder) 94 to make aconnection between the second and third decoders 87 and 88 and themonitor 93, an operation unit 95 including a mouse, keyboard, ten keys,etc. to be operated by the user, and a controller to control the entireoptical disc player 80. It should be noted that the controller 96includes a microcomputer.

[0085] As will be known from the above description, the third opticaldisc player 80 is different from the second optical disc player 60 inthat it further includes the third decoder 88 for playback of the thirdoptical disc 2 and the switch 89 is provided to selectively make aconnection between the RF circuit 82 and the first, second or thirddecoder 86, 87 or 88. It should be noted that the same circuits in thethird optical disc player 80 as those in the second optical disc player60 will not be described any more.

[0086] The third decoder 88 is provided to demodulate the third datasuch as high quality audio data etc. recorded in the second session 4defined along the outer circumference of the third optical disc 2 andhaving been EFM-modulated and supplied from the RF circuit 42 andsubject the data to decoding processes including error correction,de-interleaving and the like. The third decoder 88 provides the decodedthird data to either the I/F 94 or D/A converter 91 depending upon thetype of the data.

[0087] The controller 96 provides a control as follows in addition tothe control by the controller 75 of the second optical disc player 60.Namely, when supplied, from the subcode extraction circuit 90, withsubcodes read from one of the first, second and third optical discs 5, 6and 2, which is loaded in the third optical disc player 80, and suppliedfrom the subcode extraction circuit 90, the controller 96 determines,based on the identification data in the control block CNT and zero blockZERO in the subcode, which the optical disc set on the disc table is,the first, second or third optical disc 5, 6 or 2. When there isdetected the identification data for the second optical disc 6, recordedin the Q-channel control block CNT in the subcode shown in FIG. 3, thecontroller 96 will controls the switch 89 to connect the RF circuit 82and the second decoder 87 to each other. On the other hand, when thereis detected the identification data for the third optical disc 2,recorded in the Q-channel zero block ZERO and track number block TNO inthe subcode, the controller 96 controls the switch 89 to make aconnection between the RF circuit 82 and third decoder 88.

[0088] When there is detected identification data for a multi-sessiontype optical disc, recorded in the Q-channel address block ADR in thesubcode included in the TOC data shown in FIG. 3 or identification datafor the third optical disc 2, recorded in the zero block ZERO and tracknumber block TNO, the controller 96 will control the switch 89 to make aconnection between the RF circuit 82 and third decoder 88, and controlthe feed motor 85 to move the optical pickup 81 to a position it will beable to read data recorded in the lead-in area in the second session 4defined along the outer circumference so that data can preferentially beread from the second session 4 defined along the outer circumference.

[0089] The third optical disc player 80 constructed as above functionsas will be described below. When a play start button provided on theoperation unit 95 is pressed by the user, for example, the controller 96will drive the drive motor 84 to rotate the loaded optical disc at aconstant linear velocity while driving the feed motor 85 to move theoptical pickup 81 to a position it will be able to read TOC data such assubcodes recorded in the lead-in area provided along the innermostcircumference of the loaded optical disc. The optical pickup 81 detectsa return light from the optical disc by a photodetector (not shown),converts it to electric signal and provides it to the RF circuit 82. Thesubcode extraction circuit 90 provides the extracted subcode to thecontroller 96. The controller 96 determines, based on the identificationdata in the control block CNT and zero block ZERO in the subcode, whichthe optical disc set on the disc table is, the first, second or thirdoptical disc, or based on the identification data in the address blockADR, which the optical disc is, a multi-session type one or asingle-session type one.

[0090] When no identification data for the optical disc is the second orthird optical disc 6 or 2 can be detected in the subcode read from thelead-in area provided along the innermost circumference, the controller96 determines that the first optical disc 5 is set on the disc table andcontrols the switch 89 to connect the RF circuit 82 and first decoder 86to each other for playback of the first optical disc 5.

[0091] When the identification data for the second optical disc 6 isdetected from the control block CNT in the subcode read from the lead-inarea provided along the innermost circumference, the controller 96 willdetermine that the second optical disc 6 is set on the disc table andcontrols the switch 89 to make a connection between the RF circuit 82and second decoder 87 for playback of the second optical disc 6.

[0092] Further, when the identification data for the third optical disc2 is detected in the zero block ZERO and track number block TNO in thesubcode read from the lead-in area provided along the innermostcircumference, the controller 96 drives the feed motor 85 to move theoptical pickup 81 to a position it will be able to read TOC data such assubcodes from the lead-in area in the second session 4 defined along theouter circumference of the third optical disc 2, and control the switch89 to connect the RF circuit 82 and third decoder 88 to each other forplayback of the third optical disc 2.

[0093] Moreover, when the identification data for the multi-session typeoptical disc is detected in the address block ADR in the subcode readfrom the lead-in area provided along the innermost circumference, thecontroller 96 will control the switch 89 to make a connection betweenthe RF circuit 82 and second decoder 87 or third decoder 88, and drivethe feed motor 85 to move the optical pickup 81 to a position where itwill be able to read TOC data such as the subcodes from the lead-in areain the second session 4 defined along the outer circumference of thesecond optical disc 6 or third optical disc 2, whichever is set on thedisc table in the optical disc 81. The third optical disc player 80decodes the data read from the second session 4 by the second decoder 87or third decoder 88 for playback of the second optical disc 6 or thirdoptical disc 2 of the multi-session type.

[0094] When the user operates the operation unit 95 for reading thefirst session 3 along the inner circumference after reading the secondsession 4 defined along the outer circumference is complete, thecontroller 96 will control the switch 89 to make a connection betweenthe RF circuit 82 and first decoder 86, and drive the feed motor 85 tomove the optical pickup 81 to a position where it will be able to readTOC data such as subcodes from the lead-in area in the first session 3along the inner circumference of the second or third optical disc 6 or2. In the third optical disc player 80, the data read from the firstsession 3 is decoded by the first decoder 86 for playback of the secondor third optical disc 6 or 2.

[0095] Next, the optical disc playback system 1 including the first,second and third optical disc players 40, 60 and 80 having beendescribed in the foregoing will be described herebelow with reference toFIGS. 9A to 9C.

[0096] First, the procedure for controlling the data reading in thefirst optical disc player 40 will be described with reference to FIG.9A. In step S1, the user sets the first optical disc 5 on the disc tableof the first optical disc player 40. Next in step S2, the user pressesthe play start button on the operation unit 52 for example, and theoptical pickup 41 will be moved to the lead-in area provided along theinnermost circumference of the first optical disc 5 and read data fromthe lead-in area. Thus, the subcode extraction circuit 48 extractssubcodes from the TOC data read by the optical pickup 41 from thelead-in area of the optical disc 5. Next in step S3, the optical disc 41is moved radially of the first optical disc 5 based on the thusextracted subcode to read data from the first optical disc 5. The firstdata read from the first optical disc 5 is decoded by the first decoder46 for reproduction of audio data recorded in the first optical disc 5.

[0097] Note that when the second optical disc 6 having computer programetc. recorded therein is loaded in the first optical disc player 40, thelatter cannot decode the data by the first decoder 46 and so the secondoptical disc 6 will be ejected out of the first optical disc player 40.When a CD-Extra disc or the like is loaded in the first optical discplayer 40, the latter will read only the first session 3 along the innercircumference since the first session 3 has recorded therein audio datawhich can be decoded by the first decoder 46.

[0098] Next, the procedure for controlling the data reading in thesecond optical disc player 60 will be described with reference to FIG.9B. First in step S11, the user sets any of the first, second and thirdoptical discs 5, 6 and 2 on the disc table in the second optical discplayer 60. Next in step S12, when the play start button on the operationunit 74 is pressed by the user, the optical pickup 61 is moved to thelead-in area provided along the innermost circumference of the opticaldisc set on the disc table for reading TOC data recorded in the lead-inarea. Thus, the subcode extraction circuit 69 extracts subcodes from theread TOC data.

[0099] In step S13, the controller 75 detects identification data forthe multi-session type optical disc in the address block ADR of the Qsubcode included in the TOC data shown in FIG. 3, and determines whichthe optical disc set on the disc table is, a single-session type one ormulti-session type one. When the controller 75 determines, based on thedetected identification data, that the optical disc set on the disctable is a multi-session type one, it goes to step S14. When thecontroller 75 determines, based on the detected identification data,that the optical disc is not any multi-session type one, that is, thatthe optical disc is a single-session type one, it goes to step S18 whereit will provide such a control that TOC data is read from the lead-inarea provided along the innermost circumference and the optical pickup61 is moved radially of the optical disc based on the read TOC data forreading and reproducing the data from the optical disc.

[0100] In step S14, the controller 75 controls the feed motor 65 to movethe optical pickup 61 to a position where it will be able to read TOCdata recorded in the lead-in area in th second session 4 defined alongthe outer circumference so that data can preferentially read from thesecond session 4 defined along the outer circumference, and accesses thesecond session 4 defined along the outer circumference based on the TOCdata read by the optical pickup 61 from the lead-in area in the secondsession 4.

[0101] In step S15, the controller 75 determines which of the first andsecond decoders 66 and 67 can decode the data read from the secondsession 4 defined along the outer circumference. That is, based on theidentification data read from the control block CNT, included in the TOCdata in the lead-in area of the second session 4 defined along the outercircumference, the controller 75 determines the type of the decoderwhich is capable of decoding the data read from the second session 4.The controller 75 controls the switch 68, based on the identificationdata in the control block CNT, to make a connection between the RFcircuit 62 and the first decoder 66 or second decoder 67.

[0102] Controlling the switch 68 to make a connection between the RFcircuit 62 and the first decoder 66 or second decoder 67, the controller75 determines which of the first and second decoders 66 and 67 candecode the data read from the second session 4. When the first or seconddecoder 66 or 67 can read the data read from the second session 4, thecontroller 75 goes to step S16. On the other hand, when neither thefirst decoder 66 nor second decoder 67 can read the data from the secondsession 4, the controller 75 goes to step S19.

[0103] In step S16, the controller 75 selects either the first or seconddecoder 66 or 67 whichever can decode the data recorded in the secondsession 4, and controls the optical pickup 61 to start reading data fromthe second session 4 defined along the outer circumference. Thus thedata recorded in the second session 4 is decoded by the first or seconddecoder 66 or 67 and provided to either the speaker 71 or monitor 72depending upon the type of the decoded data.

[0104] In step S17, the controller 75 determines whether the operationunit 74 has been operated to read data from the first session 3 alongthe inner circumference. When the controller 75 has determined, based onthe input from the operation unit 74, in step S17 that data is going tobe read from the first session 3 along the inner circumference, it goesto step S18. On the other hand, when no command is entered from theoperation unit 74 and the controller 75 has determined in step that datais not to be read from the first session 3 along the innercircumference, the controller 75 goes to step S20 where it will stopreading data from the loaded optical disc.

[0105] In step S18, the controller 75 controls the feed motor 65 to movethe optical pickup 61 to a position where it will be opposite to thelead-in area of the first session 3 along the inner circumference of thesecond optical disc 6 so that it is possible to read data recorded inthe lead-in area of the first session 3 along the inner circumference,namely, data recorded in the lead-in area provided along the innermostcircumference. Thus, the optical pickup 61 will read TOC data such assubcodes from the lead-in area. The controller 75 determines, based onthe identification data in the control block CNT in the subcode includedin the TOC data in the lead-in area of the first session 3 along theinner circumference, the type of the decoder which can decode the dataread from the first session 3, and controls the switch 68 to make aconnection between the RF circuit 62 and the first decoder 66 or seconddecoder 67. In the second optical disc player 60, the data read from thefirst session 3 is decoded by the first decoder 66 or second decoder 67,and supplied via the I/F 73 to the monitor 72 on which a correspondingdisplay is made, or via the D/A converter 70 to the speaker 71 whichwill provide a corresponding audio output.

[0106] When the controller 75 determines in step S15 that the datarecorded in the second session 4 defined along the outer circumferencecannot be decoded, it goes to step S19 where it will provide such acontrol as to eject the optical disc set on the disc table out of thesecond optical disc player 60. For example, when no data can be readfrom the second session 4 because the track pitch as in the secondsession 4 defined along the outer circumference of the third opticaldisc 2 is smaller than in the first optical disc 5 and second opticaldisc 6, the controller 75 provides a control to eject, from the secondoptical disc player 60, the third optical disc as an optical disc set onthe disc table.

[0107] Note that when playing back the third optical disc 2, thecontroller 75 in the second optical disc player 60 will eject the disc 2set on the disc table out of the apparatus 60 since data recorded in thethird optical disc 2 cannot be read because the track pitch in the thirdoptical disc 2 of the single-session type is smaller than in the firstand second optical discs 5 and 6.

[0108] Next, the procedure for controlling the data reading in the thirdoptical disc player 80 will be described with reference to FIG. 9C.First in step S31, the user sets any of the first, second and thirdoptical discs 5, 6 and 2 on the disc table in the third optical discplayer 80. Next in step S32, when the play start button on the operationunit 95 of the second optical disc player 80 is pressed by the user, theoptical pickup 81 is moved to the lead-in area provided along theinnermost circumference of the optical disc set on the disc table forreading TOC data from the lead-in area. Thus, the subcode extractioncircuit 90 extracts subcodes from the read TOC data.

[0109] In step S33, the controller 96 determines, based on whetheridentification data for the third optical disc 2, recorded in the zeroblock ZERO and track number block TNO in the Q subcode shown in FIG. 3,has been detected, whether the optical disc set on the disc table is thethird optical disc 2. When the identification data for the third opticaldisc 2 has been detected and the loaded optical disc has been determinedto be the third optical disc 2, the controller 96 goes to step S34. Onthe other hand, when the identification data for the third optional disc2 has not been detected and the loaded optical disc has been determinednot to be the third optical disc 2, the controller 96 goes to step S37.

[0110] In step S34, the controller 96 controls the switch 89 to connectthe RF circuit 82 and third decoder 88 to each other, and also the feedmotor 85 to move the optical pickup 81 to a position where it will beable to read data recorded in the lead-in area of the second session 4defined along the outer circumference so that data can preferentiallyread from the session defined along the outer circumference of theloaded optical disc. Thus, TOC data is read from the lead-in area, anddata recorded in the second session 4 is read and reproduced based onthe thus read TOC data.

[0111] In step S35, the controller 96 determines whether data is to beread from the first session 3 along the inner circumference based on theinput from the operation unit 95. When the controller 96 has determinedin step S35 that data is to be read from the first session 3 at theinner circumference based on the input from the operation unit 95, itgoes to step S36. On the other hand, when there has been entered nocommand from the operation unit 95 and the controller 96 has determinedin step S35 that no data is to be read from the first session 3, thecontroller 96 goes to step S40 where it will stop reading the loadedoptical disc.

[0112] In step S36, for reading data recorded in the first session 3along the inner circumference, the controller 96 controls the feed motor85 to move the optical pickup 81 to the lead-in area of the firstsession 3 along the inner circumference of the second optical disc 6 forthe optical pickup 81 to read subcodes from the TOC data recorded in thelead-in area of the first session 3. The controller 96 determines, basedon the subcodes in the TOC data read from the lead-in area of the firstsession 3 along the inner circumference, the type of the decoder whichcan decode the data recorded in the first session 3, and controls theswitch 89 to connect the RF circuit 82 to any of the first and seconddecoders 86 and 87. In the third optical disc player 80, the data readfrom the first session 3 is decoded by the first or second decoder 86 or87, and supplied via the I/F 94 to the monitor 93 on which acorresponding display is made, or via the D/A converter 91 to thespeaker 91 which provides a corresponding audio output, depending uponthe type of the data.

[0113] If the controller 96 determines in step S33 that the optical discset on the disc table is not any third optical disc 2, it will detect instep S37 identification data for the multi-session type optical disc,recorded in the address block ADR of Q subcode included in the TOC datashown in FIG. 3 to determine which the optical disc set on the disctable is, a single-session type one or a multi-session type one. Whenthe controller 96 determines in step S37 that the optical disc set onthe disc table is a multi-session type one, it goes to step S38. On theother hand, when it determines the loaded optical disc is not anymulti-session type one, namely, that the optical disc is asingle-session type, it goes to step S39.

[0114] In step S38, the controller 96 controls the feed motor 85 to movethe optical pickup 81 to a position where it will be able to read datarecorded in the lead-in area of the second session 4 defined along theouter circumference for reading TOC data recorded in the lead-in area ofthe second session 4. The controller 96 controls the optical pickup 81to read subcodes in the TOC data in the lead-in area of the secondsession 4 defined along the outer circumference, whereby it willdetermine which of the first and second decoders 86 and 87 can decodethe data read from the second session 4 defined along the outercircumference. The controller 96 controls the switch 89 to make aconnection between the RF circuit 82 and the first decoder 86 or seconddecoder 87. After selecting a decoder which can decode data recorded inthe second session 4 defined along the outer circumference, thecontroller 96 starts reading data recorded in the second session 4. Thedata read from the second session 4 is decoded by the first decoder 86or second decoder 87, and supplied to the speaker 92 which will providea corresponding audio output or to the monitor 93 which will provide acorresponding display, depending upon the type of the data.

[0115] When the controller 96 has determined in step S37 that theoptical disc set on the disc table is not any multi-session type one,namely, that the optical disc is a single-session one, it goes to stepS39 where it will start reproducing the data read from the loadedoptical disc. More specifically, the controller 96 controls the opticalpickup 81 to read subcodes in the TOC data from the lead-in areaprovided along the innermost circumference to determine, based on thesubcode read from the optical disc, which can decode the data, the firstdecoder 86 or second decoder 87. Also, the controller 96 controls, basedon the thus read subcode, the switch 89 to make a connection between theRF circuit 82 and the first decoder 86 or second decoder 87. Then, thecontroller 96 selects one of the first and second decoders 86 and 87,which is compatible with the data recorded in the first optical disc 5or second optical disc 6, both of the single-session type, and controlsthe optical pickup 81 to start reproducing the data read from theoptical disc 5 or 6. The data thus read is decoded by the first decoder86 or second decoder 87, and supplied to the speaker 92 which willprovide a corresponding audio output or to the monitor 93 which willprovide a corresponding display, based on the type of the data.

[0116] Note that when the third optical disc 2 of the single-sessiontype is set on the disc table, the controller 96 in the third opticaldisc player 80 detects identification data for the third optical disc 2from the subcode recorded in the lead-in area provided along theinnermost circumference and determines, based on the identificationdata, whether the loaded optical disc is the third optical disc 2,controls the switch 89 to make a connection between the RF circuit 82and third decoder 88 and then the optical pickup 81 to reproduce thedata read from the third optical disc 2.

[0117] Following the procedure for controlling the data reading in theaforementioned data playback system 1, the third optical disc 2 can beplayed back solely by the third optical disc player 80 which can beauthenticated in the system 1 while the third optical disc 2 cannot beplayed back by the first and second optical disc players 40 and 60 whichcannot be authenticated in the system 1. Therefore, even in case thesecond optical disc player 60 has a function to write informationsignals to a recordable optical disc such as CD-R or CD-RW, for example,data recorded in the second session 4 of the third optical disc 2 at atrack pitch smaller than in the first and second optical discs 5 and 6cannot be read, so that the third optical disc 2 will be ejected fromthe optical disc player. Thus, it is possible to prevent data fromillegally being copied digitally to a recordable optical disc.

[0118] Next, another example of the procedure for controlling the datareading in the second optical disc player 60 will be described withreference to FIG. 10. In this second optical disc player 60, when datacannot be read from the second session 4, the loaded optical disc is notrejected but access is made to the second session 4 for reading datarecorded there. Namely, this second optical disc player 60 is acircumvention device which positively prevents any optical disc playernot authenticated for reading the third optical disc 2 from reading thethird optical disc 2.

[0119] First in step S51, the user sets any of the first optical disc 5,second optical disc 6 or third optical disc 2 on the disc table of thesecond optical disc player 60. Next in step S52, when the user pressesthe play start button on the operation unit 74 for example, the opticalpickup 61 in the second optical disc player 60 is moved to the lead-inarea provided along the innermost circumference of the optical disc seton the disc table for reading TOC data recorded in the lead-in area.Thus, the subcode extraction circuit 69 extracts subcodes from the thusread TOC data.

[0120] In step S53, the controller 75 detects identification data forthe multi-session type optical disc, recorded in the address block ADRof the Q subcode included in the TOC data as shown in FIG. 3 anddetermines which the optical disc set on the disc table is, asingle-session type one or a multi-session type one. When the controller75 has determined in step S53 that the optical disc set on the disctable is a multi-session type one, it goes to step S54. On the otherhand, when the controller 75 has determined in step S53 that the opticaldisc is not any multi-session type one, namely, that the optical disc isa single-session type one, it goes to step S58 where it will control theoptical pickup 61 to read TOC data from the lead-in area provided alongthe innermost circumference and play back the loaded optical disc basedon the thus read TOC data.

[0121] In step S54, for preferentially reading data from the secondsession 4 defined along the outer circumference, the controller 75controls the feed motor 65 to move the optical pickup 61 to a positionwhere it will be able to read TOC data recorded in the lead-in area ofthe second session 4 defined along the outer circumference.

[0122] In step S55, the controller 75 determines, based onidentification data recorded in the control block CNT, included in thesubcode read from the lead-in area of the second session 4, which of thefirst and second decoders 66 and 67 can decoded the data read from thesecond session 4 defined along the outer circumference. Based on thethus read identification data, the controller 75 controls the switch 68to make a connection between the RF circuit 62 and the first decoder 66or second decoder 67.

[0123] Based on the thus read identification data, the controller 75controls the switch 68 to determine which of the first and seconddecoders 66 and 67 can decode the data. When the first or second decoder66 or 67 can decode the data read from the second session 4, thecontroller 75 goes to step S56. On the other hand, when the first orsecond decoder 66 or 67 cannot decode the data read from the secondsession 4, the controller 75 goes to step S58. That is, when data cannotbe read from the second session 4 defined along the outer circumferenceof the third optical disc 2, the controller 75 of the second opticaldisc player 60 will not provide a control to eject the third opticaldisc 2 as a loaded optical disc out of the second optical disc player 60but will control the feed motor 65 to move the optical pickup 61 to aposition where it will be opposite to the second session 4 along theinner circumference of the third optical disc 2 for reading datarecorded in the second session 4.

[0124] In step S56, the controller 75 selects, based on theidentification data, a decoder which can decode the data recorded in thesecond session 4, and controls the optical pickup 61 to start readingdata from the second session 4 defined along the outer circumference.The data recorded in the second session 4 is decoded by the firstdecoder 66 or second decoder 67, and supplied to the speaker 71 whichwill provide a corresponding audio output or to the monitor 72 whichwill provide a corresponding video output, depending upon the type ofthe data.

[0125] In step S57, the controller 75 determines, based on a commandsupplied from the operation unit 74 operated by the user, whether datais to be read from the second session 4 along the inner circumference.When the controller 75 has determined in step S57 based on the commandfrom the operation unit 74 that data is to be read from the secondsession 4 along the inner circumference, it goes to step S58. On theother hand, when no command is supplied from the operation unit 74 andthe controller 75 has determined in step S57 that data is not to be readfrom the second session 4, the controller 75 goes to step S59 where itwill stop playing back the loaded optical disc.

[0126] In step S58, to read TOC data such as subcodes recorded in thelead-in area in the second session 4 along the inner circumference,namely, in the lead-in area provided along the innermost circumference,the controller 75 drives the feed motor 65 to move the optical pickup 61to a position where it will be opposite to the lead-in area in thesecond session 4 along the inner circumference of the second opticaldisc 6. The controller 75 determines, based on the data such as subcodesin the TOC data read from the lead-in area of the second session 4 alongthe inner circumference, the type of the decoder capable of decodingdata recorded in the first session 3, and controls the switch 68 to makea connection between the RF circuit 62 and the first decoder 66 orsecond decoder 67. In the second optical disc player 60, the thus readdata is decoded by the first or second decoder 66 or 67, and suppliedvia the I/F 73 to the monitor 72 which will provide a correspondingdisplay or via the D/A converter 70 to the speaker 71 which will providea corresponding audio output.

[0127] In the second optical disc player 60, even if reading data fromthe third optical disc 2 is tried, it is not possible since the trackpitch in the second session 4 is smaller than in the first and secondoptical discs 5 and 6, and the optical pickup 61 is forced to access thefirst session 3 along the inner circumference. Therefore, even when thesecond optical disc player 60 has a function to write informationsignals to a recordable optical disc such as CD-R or CD-RW for example,it is possible to prevent data recorded in the second session 4 of thethird optical disc 2 from illegally being recorded digitally to such arecordable optical disc since data cannot be read from the secondsession 4.

[0128] Also, a still another example of the procedure for controllingthe data reading in the second optical disc player 60 will be describedwith reference to FIG. 11. In this second optical disc player 60, whenthe optical disc set on the disc table is detected to be the thirdoptical disc 2, access is made to the first session 3 along the innercircumference but not o the second session 4.

[0129] First in step S61, the user sets any of the first optical disc 5,second optical disc 6 or third optical disc 2 on the disc table of thesecond optical disc player 60. Next in step S62, when the user pressesthe play start button on the operation unit 74 for example, the opticalpickup 61 is moved to the lead-in area provided along the innermostcircumference of the optical disc set on the disc table for reading TOCdata recorded in the lead-in area. Thus, the subcode extraction circuit69 extracts subcodes from the thus read TOC data.

[0130] In step S63, the controller 75 determines, depending upon whetherthere has been detected identification data for the third optical disc2, recorded in the zero block ZERO and track number block TNO of the Qsubcode as shown in FIG. 3, whether the optical disc set on the disctable is the third optical disc 2. When the controller 75 has determinedbased on the identification data detected in step S63 that the opticaldisc set on the disc table is the third optical disc 2, it goes to stepS64. On the other hand, when the controller 75 has determined in stepthat the optical disc set on the disc table is not the third opticaldisc 2, it goes to step S65.

[0131] In step S64, the controller 75 drives the feed motor 65 to movethe optical pickup 61 to a position where it will be opposite to thelead-in area of the first session 3 along the inner circumference andread TOC data such as subcodes recorded in the lead-in area of thesecond session 4 along the inner circumference of the optical disc. Thecontroller 75 controls the optical pickup 61 to read identification datarecorded, in the control block CNT in the subcode in the TOC data readfrom the lead-in area of the second session 4 along the innercircumference, determines type of the decoder capable of decoding thedata recorded in the second session 4, and controls the switch 68, basedon the identification data, to make a connection between the RF circuit62 and the first decoder 66 or second decoder 67. In the second opticaldisc player 60, the data read from the first session 3 is decoded by thefirst decoder 66 or second decoder 67, and supplied via the I/F 73 tothe monitor 72 which will provide a corresponding video output or viathe D/A converter 70 to the speaker 71 which will provide acorresponding audio output.

[0132] When the controller 75 has determined in step S63 based on theidentification data that the optical disc set on the disc table is notthe third optical disc 2, it goes to step S65 where it will detectidentification data for the multi-session type optical disc, recorded inthe address block ADR of the Q subcode included in the TOC data as shownin FIG. 3, and determine which the optical disc set on the disc tableis, a single-session type one or a multi-session type one. When thecontroller 75 has determined in step S65 that the optical disc set onthe disc table is a multi-session type one, it goes to step S66. On theother hand, when the controller 75 has determined in step S65 that theloaded optical disc is not any multi-session type one, namely, that itis a single-session type one, it goes to step S64 where it will accessthe second session 4 defined along the outer circumference of the loadedoptical disc.

[0133] In step S66, the controller 75 controls the feed motor 65 to movethe optical pickup 61 to a position where it will be able to read datarecorded in the lead-in area of the second session 4 defined along theouter circumference for access to that second session 4. In step S67,the controller 75 reads the control block CNT in the subcode in thelead-in area of the second session 4 defined along the outercircumference to select either the first decoder 66 or second decoder 67and controls the switch 68 based on the read control block CNT. Thecontroller 75 controls the optical pickup 61 to start reading data fromthe second session 4 defined along the outer circumference. The dataread from the second session 4 is decoded by the first decoder 66 orsecond decoder 67, and supplied to the speaker 71 or monitor 72,depending upon the type of the data.

[0134] In step S68, the controller 75 determines, based on an operationsignal entered from the operation unit 74, whether data is to be readfrom the first session 3 along the inner circumference. When thecontroller 75 has determined, based on the input from the operation unit74, that data is to be read from the first session 3 defined along theinner circumference, it goes to step S64 where it will access the firstsession 3 and reproduce the data read from the first session 3. On theother hand, when no operation signal is entered from the operation unit74 and it is determined in step S68 that data is not to be read from thefirst session 3, the controller goes to step S69 where it will stopreading the loaded optical disc.

[0135] In the aforementioned second optical disc player 60, when data isgoing to be read from the third optical disc 2, TOC data in the lead-inarea provided along the innermost circumference is read and the loadedoptical disc is detected to be the third optical disc 2, a forced accessis made to the first session 3 without access to the second session 4.Therefore, even in case the second optical disc player 60 has a functionto record information signals to a recordable optical disc such as CD-Ror CD-RW, it is possible to prevent data recorded in the second session4 of the third optical disc 2 from illegally being recorded digitally tosuch a recordable optical disc since no data can be read from the secondsession 4.

INDUSTRIAL APPLICABILITY

[0136] As having been described in the foregoing, the optical discaccording to the present invention has data recorded in the first formatin the first session along the inner circumference, data recorded in thesecond format in the second format in which the track pitch is smallerthan in the first session along the inner circumference, andidentification data for the multi-session type optical disc in thelead-in area in the first session along the inner circumference.Therefore, in a conventional optical disc player used for playing backthis optical disc, the identification data for the multi-session typeoptical disc, recorded in the lead-in area, is detected and access ismade to the second session defined along the outer circumference, fromwhich no data can be read. With this optical disc, it is possible toprevent data in the second session defined along the outer circumferencefrom being read by the second optical disc player.

[0137] Also, since the optical disc according to the present inventionhas recorded in the lead-in area identification data for themulti-session type optical disc, a optical disc player capable ofreading data from the second session can preferentially read data fromthe second session.

[0138] In the optical disc player according to the present invention,when the second session cannot be read, the recording medium can beejected or a forced access be made to the first session, whereby it ispossible to prevent the data recorded in the second session from beingreproduced by any unauthorized optical disc player, namely, to preventsuch data from illegally being copied digitally, for example. Thus, thecopyright for the data can be protected.

1. An optical disc comprising: at least a first recording area andsecond recording area; a first lead-in area provided along the innercircumference of the first recording area; a first lead-out areaprovided along the outer circumference of the first recording area; asecond lead-in area provided between the outer circumference of thefirst lead-out area and the second recording area; and a second lead-outarea is provided along the outer circumference of the second recordingarea; the second lead-in area, second recording area and second lead-outarea being formed at a smaller track pitch than in the first lead-inarea, first recording area and first lead-out area, and the firstlead-in area has recorded therein identification data for the existenceof at least the second recording area.
 2. The optical disc of claim 1,wherein the first lead-in area has recorded therein mediumidentification data for an optical disc which is a recording medium inwhich the second lead-in area, second recording area and second lead-outarea are formed at a smaller track pitch than in the first lead-in area,first recording area and first lead-out area.
 3. The optical disc ofclaim 1, wherein the second lead-in area has recorded therein data typeidentification data for the type of the data recorded in the secondrecording area.
 4. An optical disc playback method comprising steps of:reading identification data recorded in an optical disc loaded in anoptical disc player; and starting reading data from a second recordingarea of the optical disc loaded in the optical disc player when it isdetermined based on the read identification data that the loaded opticaldisc is a one having at least first and second recording areas, a firstlead-in area provided along the inner circumference of the firstrecording area, a first lead-out area provided along the outercircumference of the first recording area, a second lead-in areaprovided between the outer circumference of the first lead-out area andsecond recording area, and a second lead-out area provided along theouter circumference of the second recording area.
 5. The method of claim4, further comprising a step of ejecting the loaded optical disc fromthe optical disc player either when the data read from the secondrecording area cannot be decoded or when data recorded in the secondrecording area cannot be read.
 6. The method of claim 4, furthercomprising a step of reading data from the first recording area when thedata read from the second recording area cannot be decoded.
 7. Themethod of claim 4, further comprising steps of: reading data recorded inthe second lead-in area before reading data from the second recordingarea; and selecting another decoder based on the data read from thesecond lead-in area.
 8. The method of claim 4, further comprising a stepof reading data recorded in the first recording area when a command forreading the data recorded in the first recording area is entered aftercompletion of reading the data recorded in the second recording area. 9.The method of claim 4, further comprising a step of reading datarecorded in a recording area based on the data read from a lead-in areawhen the loaded optical disc is determined to be a one having thelead-in area, recording area provided along the outer circumference ofthe lead-in area, and a lead-out area provided along the outercircumference of the recording area.
 10. An optical disc playback methodcomprising steps of: reading medium identification data for an opticaldisc type from a lead-in area of an optical disc loaded in an opticaldisc player; and reading data from a second recording area when it isdetermined based on the read medium identification data that the opticaldisc loaded in the optical disc player is a one in which a secondlead-in area, second recording area provided along the outercircumference of the second lead-in area and a second lead-out areaprovided along the outer circumference of the second recording area areformed at a smaller track pitch than in a first lead-out area providedalong the inner circumference of the second lead-in area, firstrecording area provided along the inner circumference of the firstlead-out area and a first lead-in area provided along the outercircumference of the first recording area.
 11. The method of claim 10,further comprising steps of: reading data recorded in the second lead-inarea before reading data from the second recording area; and selectinganother decoder based on the data read from the second lead-in area. 12.The method of claim 10, further comprising a step of reading datarecorded in the first recording area when a command for reading the datarecorded in the first recording area is entered after completion ofreading the data recorded in the second recording area.
 13. An opticaldisc playback method comprising steps of: reading medium identificationdata for an optical disc type from a lead-in area of an optical discloaded in an optical disc player; and reading data from a firstrecording area when it is determined based on the read mediumidentification data that the optical disc loaded in the optical discplayer is a one in which a second lead-in area, second recording areaprovided along the outer circumference of the second lead-in area and asecond lead-out area provided along the outer circumference of thesecond recording area are formed at a smaller track pitch than in afirst lead-out area provided along the inner circumference of the secondlead-in area, first recording area provided along the innercircumference of the first lead-out area and a first lead-in areaprovided along the outer circumference of the first recording area. 14.The method of claim 13, further comprising a step of starting readingdata from the second recording area of the loaded optical disc when itis determined that the loaded optical disc is a one having at least thefirst recording area, first lead-in area provided along the innercircumference of the first recording area, first lead-out area providedalong the outer circumference of the first recording area, secondlead-in area provided between the outer circumference of the firstlead-out area and second recording area, and the second lead-out areaprovided along the outer circumference of the second recording area. 15.The method of claim 14, further comprising a step of reading datarecorded in the first recording area when a command for reading the datarecorded in the first recording area is entered after completion ofreading the data recorded in the second recording area.
 16. The methodof claim 14, further comprising a step of reading data recorded in arecording area based on the data read from a lead-in area when theloaded optical disc is determined to be a one having the lead-in area,recording area provided along the outer circumference of the lead-inarea, and a lead-out area provided along the outer circumference of therecording area.
 17. An optical disc player comprising: a drive unit torotate an optical disc loaded in the optical disc player; an opticalpickup to read data from the loaded optical disc; an actuator to movethe optical pickup radially of the loaded optical disc; and a controllerto control the operation of at least the actuator while identifying thetype of the loaded optical disc based on identification data read by theoptical pickup from the loaded optical disc; the controller controllingthe actuator to move the optical pickup and causing the optical pickupto start reading data from a second recording area of the loaded opticaldisc when it is determined that the loaded optical disc is a one havingat least first and second recording areas, a first lead-in area providedalong the inner circumference of the first recording area, a firstlead-out area provided along the outer circumference of the firstrecording area, a second lead-in area provided between the outercircumference of the first lead-out area and second recording area and asecond lead-out area provided along the outer circumference of thesecond recording area.
 18. The apparatus of claim 17, further comprisingat least a decoder which is supplied with output signals from theoptical pickup, and wherein when the data read from the second recordingarea cannot be decoded, the controller causes the loaded optical disc tobe ejected from the apparatus.
 19. The apparatus of claim 17, whereinthe controller causes the optical disc loaded in the apparatus to beejected when it is determined that no data can be read from the secondrecording area of the loaded optical disc.
 20. The apparatus of claim17, further comprising at least a decoder which is to be supplied withoutput signals from the optical pickup, and wherein when the data readfrom the second recording area cannot be decoded, the controllercontrols the actuator to move the optical pickup for reading data fromthe first recording area of the optical disc.
 21. The apparatus of claim17, further comprising multiple decoders which are to be supplied withoutput signals from the optical pickup, the controller controlling theactuator to move the optical pickup to a position where it will beopposite to the second lead-in area to read data recorded in the secondlead-in area and selecting, based on the data read from the secondlead-in area, one of the multiple decoders that is to be supplied withoutput signals from the optical pickup.
 22. The apparatus of claim 17,wherein the controller provides a control for reading data recorded inthe first recording area when a command for reading the data recorded inthe first recording area is entered after completion of reading the datarecorded in the second recording area.
 23. The apparatus of claim 17,wherein the controller provides a control for reading data recorded in arecording area based on the data read from a lead-in area when theloaded optical disc is determined to be a one having the lead-in area,recording area provided along the outer circumference of the lead-inarea, and a lead-out area provided along the outer circumference of therecording area.
 24. An optical disc player comprising: a drive unit torotate an optical disc loaded in the optical disc player; an opticalpickup to read data from the loaded optical disc; an actuator to movethe optical pickup radially of the loaded optical disc; and a controllerto control the operation of at least the actuator while identifying thetype of the loaded optical disc based on identification data read by theoptical pickup from the loaded optical disc; the controller controllingthe actuator to move the optical pickup and causing the optical pickupto start reading data from a second recording area of the loaded opticaldisc when it is determined based on the medium identification data thatthe loaded optical disc is a one in which a second lead-in area, secondrecording area provided along the outer circumference of the secondlead-in area and a second lead-out area provided along the outercircumference of the second recording area are formed at a smaller trackpitch than in a first lead-out area provided along the innercircumference of the second lead-out area, first recording area providedalong the inner circumference of the first lead-out area and a firstlead-in area provided along the inner circumference of the firstrecording area.
 25. The apparatus of claim 24, further comprisingmultiple decoders which are to be supplied with output signals from theoptical pickup, and wherein the controller controls the actuator to movethe optical pickup to a position where it will be opposite to the secondlead-in area to read data recorded in the second lead-in area andselects, based on the data read from the second lead-in area, one of themultiple of decoders that is to be supplied with output signals from theoptical pickup.
 26. The apparatus of claim 24, wherein the controllerprovides a control for reading data recorded in a recording area basedon the data read from a lead-in area when the loaded optical disc isdetermined to be a one having the lead-in area, recording area providedalong the outer circumference of the lead-in area, and a lead-out areaprovided along the outer circumference of the recording area.
 27. Anoptical disc player comprising: a drive unit to rotate an optical discloaded in the optical disc player; an optical pickup to read data fromthe loaded optical disc; an actuator to move the optical pickup radiallyof the loaded optical disc; and a controller to control the operation ofat least the actuator while identifying the type of the loaded opticaldisc based on identification data read by the optical pickup from theloaded optical disc; the controller controlling the actuator to move theoptical pickup and causing the optical pickup to start reading data froma first recording area of the loaded optical disc when it is determinedbased on the medium identification data that the loaded optical disc isa one in which a second lead-in area, second recording area providedalong the outer circumference of the second lead-in area and a secondlead-out area provided along the outer circumference of the secondrecording area are formed at a smaller track pitch than in a firstlead-out area provided along the inner circumference of the secondlead-out area, first recording area provided along the innercircumference of the first lead-out area and a first lead-in areaprovided along the inner circumference of the first recording area. 28.The method of claim 27, wherein the controller controls the actuator tothe optical pickup and causes the pickup to start reading data from thesecond recording area of the loaded optical disc when it is determinedthat the loaded optical disc is a one having at least the firstrecording area, first lead-in area provided along the innercircumference of the first recording area, first lead-out area providedalong the outer circumference of the first recording area, secondlead-in area provided between the outer circumference of the firstlead-out area and second recording area and second lead-out areaprovided along the outer circumference of the second recording area. 29.The apparatus of claim 27, wherein the controller provides a control forreading data recorded in the first recording area when a command forreading the data recorded in the first recording area is entered aftercompletion of reading the data recorded in the second recording area.30. The apparatus of claim 27, wherein the controller provides a controlfor reading data recorded in a recording area based on the data readfrom a lead-in area when the loaded optical disc is determined to be aone having the lead-in area, recording area provided along the outercircumference of the lead-in area, and a lead-out area provided alongthe outer circumference of the recording area.
 31. An optical discrecording method comprising steps of: forming a first lead-in area andfirst lead-out area at a first track pitch from the inner circumferenceof an optical disc toward the outer circumference; forming a secondlead-in area, second recording area and a second lead-out area at asecond track pitch smaller than the first track pitch toward the outercircumference of the first lead-out area; and recording, to the firstlead-in area, at least identification data for the existence of thesecond recording area.
 32. The method of claim 31, wherein the firstlead-in area has recorded therein medium identification data indicatingthat the track pitch of the second lead-in area, second recording areaand second lead-out area is smaller than in the first lead-in area,first recording area and first lead-out area.
 33. The method of claim32, wherein the medium identification data is included in subcodes to berecorded to the first lead-in area.
 34. The method of claim 31, whereintype identification data indicating the type of data recorded in thesecond recording area is recorded to the second lead-in area.
 35. Themethod of claim 32, wherein the medium identification data is includedin subcodes to be recorded to the first lead-in area.